Space Sails Could Bring Used Rockets Back To Earth 76
GordonCopestake writes "An article from New Scientist proposes that all new spacecraft have sails attached to bring them back to earth — a measure that would reduce the amount of garbage in space. From the article: 'The risk to spacecraft from a collision with space debris could be reduced by equipping launchers with a gossamer-thin "sail." The idea is to deploy the sail after the rocket has released its payload to amplify the drag of the last vestiges of the atmosphere, and so force the rocket out of orbit.'"
Wired has a related story about the risks faced by the space shuttles as they share orbits with tons of drifting space debris. "... in the 54 missions from STS-50 through STS-114, space junk and meteoroids hit shuttle windows 1,634 times necessitating 92 window replacements. In addition, the shuttle's radiator was hit 317 times, actually causing holes in the radiator's facesheet 53 times."
Choke (Score:1, Funny)
Re:Choke (Score:4, Funny)
Please, go back to YouTube. Your peers there are missing you.
I pray he never learns the word 'sheeple'.
And the old junk? (Score:5, Interesting)
Actually, it might, for the larger stuff (Score:4, Interesting)
Re:And the old junk? (Score:5, Informative)
The debris in low orbits where the Shuttle operates will return within just a few years. Higher than that means it stays up longer.
If an object is orbiting twice as high as the shuttle, about 500 miles, it'll stay up roughly a couple centuries. Just a bit higher than that and you're measuring orbital lifetimes in millennia.
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The debris in low orbits where the Shuttle operates will return within just a few years. Higher than that means it stays up longer.
Do you know how much of a difference the size of the debris makes? The wikipedia orbital debris entry [wikipedia.org] doesn't say.
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Don't be a programmer-bureaucrat; someone who substitutes marketing buzzwords and software bloat for verifiable improvements.
Re:And the old junk? (Score:5, Informative)
Densities of materials vary widely, but as a rule of thumb, mass increases with the cube of an object's size, but drag only increases with the square.
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I found the notion pretty impressive, that a piece of shrapnel, only 1 g in weight, is like a 600 kg (~1323 pounds) bike, crashing at them with 600 km/h (~373 mph). Imagine that, with the size of a pencil tip, hitting a window. Now imagine a piece of half a ton doing the same...
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It depends tremendously on the orbit and the object. Some 'objects', like dumped urine or water, submlimate. They're still deadly if they hit you from even a slightly different orbit, since we're talking about base speeds of roughly 18,000 mph in low earth orbit: it's the difference between the orbits that determines their relative velocity, and that's easily as much as 10%. (Head-on collisions are basically unheard of: one object would have to be orbiting the other way entirely, and no one does that due to
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Qualifier: polar orbits allow this geometry of impact.
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Mass Catcher (Score:3, Insightful)
I wonder if we could operate a remote-controlled Mass Catcher [nasa.gov]? The one designed for the 1975 Stanford Summer Study would do if you left off the intake grid of cables. It would be a rotating Kevlar cone. Centrifugal force would hold loose regolith in place, which would act to absorb the impact of the intercepted debris. The same rotation would also act as artificial gravity to prevent the escape of secondary splash debris. Using a pellet launcher as a thruster would be safe, since the pellets would be t
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How effective are these sails when they themselves are punctured by debris?
99.999% as effective. At orbital altitudes air doesn't behave like a continuum, just like independent molecules bouncing around. This is bad if you're trying to design a wing (pressure doesn't affect flow in the same way and your lift to drag ratios suck) but great if you're designing a parachute (a small hole will let molecules through at the site of the hole, but won't affect their absorption/reemission or their reflection elsewh
Ban space weapons as well (Score:2, Insightful)
Such ban is worthless in so many ways (Score:3, Interesting)
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The solution is obvious - nuke the Chinks.
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You make the assumption that North Korea started mixing household chemicals in their backyard and instantly created their nukes. They had LOTS of help from other countries. The point of a world-wide ban is that you shut down these kinds of conduits. How do you know that China is secretly building nuclear subs BTW? Countries have ways of verifying through espionage.
If there's a space weapons ban, there's practically no way to test without the whole world coming down on you. Your analogies aren't the sa
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And that is why China is paranoid about the outside world with our aircrafts and boats. We are working hard to spy and to know EXACTLY what their count is, while China is doing their utmost to keep it hidden. 1935 Germany was the same way. In fact, all countries that are gearing up for a war will be that way. Back in the 50's and 60's, America and USSR KNEW that each other were spying on th
Woah (Score:4, Interesting)
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Getting bombarded by our own crap (Score:2, Insightful)
The universe is mocking us for not thinking ahead. Again.
And our reaction? "Let's make those pieces bigger!"
Re:Getting bombarded by our own crap (Score:4, Interesting)
Don't anthropomorphise the universe. It doesn't like it. All kidding aside, I am not sure that you said anything. Do you only want to put small things into orbit? Or are you saying we should make sure "what goes up, must come down?"
I think you are saying adding the sails would make the debris bigger, and thus even more of a problem.
Maybe you should have just said "the road to hell is paved with good intentions" and left it at that.
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We are the tubgirl of Sol system.
Comment removed (Score:3, Informative)
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Bad idea (Score:5, Insightful)
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Thousands of smaller lumps would have a massively larger surface area, so wouldn't they fall a lot faster? So within a year or so they'd be gone, no?
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Space Debris Big Game Hunting Safaris (Score:3, Funny)
Issue licenses to commercial space flight providers. Their spacecraft would be fitted with big-ass laser canons. Rich folks would fork out a few million for the privilege of bagging some space debris.
Each flight would have "Space Hunting Guides & Skinners," grizzled, experienced former government astronauts. The skinner would ensure that there was no smaller junk left over after the kill. It would be burned up in the nightly campfire with a yet-to-be-determined technology.
The guide would say cool
Re:Proud to be White (Score:4, Funny)
Now that you mention it... Maybe we should try launching politicians up there to collect the debris. Or bankers.
Can we build something cheap enough to launch them all?
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Moon or obiting junkyard (Score:2)
Re:Moon or obiting junkyard (Score:5, Informative)
Space is not earth.
Moving things in space and keeping them from crashing into the atmosphere requires energy. Energy means fuel and fuel means you need to pay to send it up. Docking objects in space requires complex electronics which means even more mass to send up.
Recycling requires a highly advanced and complex industrial base which doesn't exist in space. If it did then you wouldn't need the junk since you can mine your own raw materials.
mission expectation (Score:1, Offtopic)
You're going to get a hole in your radiator.
You're going to get hit in the window 30 times.
Two windows will need to be replaced.
Hit or Miss or Hit (Score:5, Insightful)
"For the final stage of an Ariane 5 launcher, the conical sail would need to have an area of about 350 square metres and be supported by an inflatable mast 12 metres long."
And the expected time to reentry is 25 years.
Good luck on keeping something inflated in space for 25 years. And that's not even considering the probability that the the mast, and the much higher probability that the large sail, will be hit by orbiting debris during that time and torn to shreds
Re:Hit or Miss or Hit (Score:4, Insightful)
Inflate it with a plastic foam resin that hardens into a "solid" mast.
Making solar sails (Score:4, Interesting)
Here is my idea for making an extra light solar sail:
http://kim.oyhus.no/Solar_sail.html [oyhus.no]
Kim0
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No, it is not aero-breaking,
because of all the holes, which let air through.
Kim0
This job is rather like... (Score:3, Interesting)
It's rather like taking a stroll down Main St. in one of those western cowboy movies.
Anyone know how powerful a big electro magnet would have to be to suck debris within say... a mile, towards it?
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Water and Aerogels (Score:2)
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Where's Scotty when you need him? (Score:3, Funny)
Space sails? That's so low tech.
It's obvious we need deflector dishes and shields.
Star Trek has taught us that much!
This is the reason space travel will never happen (Score:2)
The problem with space travel won't be the engines or how to recycle the used food, it'll be all the rocks constantly beating on the hull.
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Such a Waste (Score:4, Interesting)
I think that any mass in orbit is far more valuable there than back on earth. It still has all the energy the owner has paid for by launching it in the first place, and at ~$1000 per kg in LEO that is nothing to sneeze at. I think the solar sails should be used to cart the stuff into a higher orbit where the parts can be stored with less effort.
The problem is that whatever we sent up is not built for reusability it would seem. Without a decent plan to produce something from space junk I guess nobody is going to worry about where the hardware in orbit goes beyond its eol, it has paid for the launch costs already why worry about much costlier manufacturing in orbit. Then it is also safer to just drop the stuff. This proposal is more of the same shortsighted thinking however. We will continuously put stuff into orbit, why let it decay back to earth if there could be a continuous reuse of material in orbit? Something goes up nothing comes down!
The space junk problem could finally lead to better planning for the future. Somebody could come up with an in orbit manufacturing and launch facility which buys the energy + material value of your satellite/booster. Its main bussiness would be in orbit manfacturing and launch of hardware with a certain orbit.
I would venture a guess and say that we already have the technology to make this work today. So it is time to check whether this could become a viable business model.
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PS, your cost is incorrect, especially if we're just talking energy. It takes only somewhere on the order of $10-20 per kg in energy to put something in orbit. The cost of objects in orbit isn't due to the energy of the objects. Currently, the Russians are the cheapest. And they might go down to $3,000-4,000 per kg to put things in orbit.
And what will a space salvage busin
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I made a silly mistake about calculating the cost to orbit, it had something to do with converting between pounds and kilograms. I assumed $2000/pound through a russian launch (my source: www.futron.com/pdf/resource_center/white_papers/FutronLaunchCostWP.pdf).
I agree with you that looking only at the energy would be too narrow a focus. Launch costs include ground operations and other things whereas the launcher itself isn't even the biggest part of the costs.
One could use different technologies once in orb
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I think that any mass in orbit is far more valuable there than back on earth. It still has all the energy the owner has paid for by launching it in the first place, and at ~$1000 per kg in LEO that is nothing to sneeze at.
There's already plenty of mass in space, we can cart up rocks from the moon for a pittance if we wanted to. The problem is that all that mass is useless since the cost of manufacturing things in space would be insane.
I think the solar sails should be used to cart the stuff into a higher orbit where the parts can be stored with less effort.
They aren't putting solar sails on these things in case you haven't realized.
So you want to spend mass to send up complex (and fragile likely) solar sails with complex guidance systems? Solar sails which, asfaik, have never been shown to actually work yet and that are not used by any existing s
Competing technology (Score:2)
why bring them back down? (Score:3, Interesting)
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Are you planning to build a space station from flecks of paint, foam, and metal? Unlike in cartoons [slashdot.org], you can't just build anything from random metal parts.
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First of all because atmospheric drag slows things down and robs them of energy. Going to a higher orbit requires increasing velocity and adding energy. In other words, the laws of physics prevent your scheme from working.
There are other reasons I can think of but I think this one is enough.
I have an idea (Score:1)
And it involves sending a lot of baseball players to space, with steady supplies of baseball bats.
garbage collection (Score:2)
Why not take this further. Shoot up rockets with big sails attached for the sole purpose of collecting space debris. put them in an orbit then deploy their sails or parachutes so they will catch a swath of debris. if the rocket is traveling slightly faster than the debris the sail wont be punctured and it will fill up before losing its velocity and then falling out of orbit.
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"Terminator Tethers" might be cheaper (Score:1)
http://www.tethers.com/TT.html [tethers.com]
I saw Robert L Forward talk about this at a con years ago.
Tethers better than sails? (Score:2)
Instead of atmospheric drag a conductive tether moving through the Earth's magnetic current generates a current and radiates the heat from tether resistance. The dissipated energy will eventually bring the satellite down. The technique has been developed by Tethers Unlimited and the late Dr. Robert Forward [wikipedia.org]
http://www.tethers.com/TT.html [tethers.com]